HD1200/1 - JL Audio Monoblock 1200W Subwoofer Speaker Amplifier Patented Single Cycle Control technology delivers reference-grade audio Tightly regulated, intelligent power supply maintains full power at any impedance from 1.5-4 ohms and at any supply voltage from 11v-14.5v Fully variable frequency selection from 50-500Hz with detented, calibrated potentiometer. Remote level control with optional controller Dimensions: 10.74 in W x 8.29 in D x 1.5 in H